Apparatus and methods for bone, tissue and duct dilatation

ABSTRACT

Apparatus and methods are disclosed for medical treatment comprising bone, tissue or duct dilatation using inflatable dilatation elements together with apparatus and techniques for tensioning, stretching, folding, and/or wrapping the dilatation elements externally as well as in situ to facilitate insertion, positioning and withdrawal procedures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Division of U.S. Ser. No. 10/674,031, filed Sep.29, 2003, now U.S. Pat. No. 7,488,337 issued Feb. 10, 2009, which claimsthe benefit of U.S. Provisional application Ser. No. 60/414,766, filedSep. 30, 2002.

FIELD OF THE INVENTION

The present invention relates generally to methods and apparatus forbone, tissue and duct dilatation, for example in surgically treatingbone deformities and bones suffering from or predisposed to fracture orto collapse, particularly spinal fractures such as those commonlyresulting from osteoporosis. In the example of bone treatment, aninflatable balloon element in accordance with the present invention isinserted into an interior region, cavity or passage of a damaged,collapsed, or deformed bone segment; and, thereafter the balloon elementis inflated to form, enlarge or support the interior bone region therebyto effect a desirable realignment of the damaged bone segment withadjacent bone portions. In alternative embodiments of this invention,following the dilatation step, the balloon element may be collapsed andwithdrawn from the interior bone region utilizing the special methodsand apparatus of this invention or, in some embodiments, the dilatedballoon element may be left in place, and the cavity or the interior ofthe dilated balloon element may be filled with a suitable supportmaterial. The present invention has particular application in, but isnot limited to, treatment of vertebral body compression fractures.

BACKGROUND OF THE INVENTION

A number of diseases, illnesses and other medical conditions aretreatable at least in part by dilatation of a bone, tissue or duct. Forexample, medical conditions and/or physical injuries can lead to orpredispose a bone to deformity, such as a fracture. A familiar exampleis osteoporosis, in which bones lose calcium and break more easily. Thehuman spinal column, comprised of interconnected vertebrae or vertebralbodies, has proven to be especially susceptible to the effects ofosteoporosis. A vertebral body weakened by osteoporosis can fracturefrom a fall, or simply during routine activities. When a vertebral bodyfractures, it can collapse and change the shape of the spine. Thedamaged portion of the spine becomes shorter, and the rest of the spineabove the broken vertebral body bends forward. As additional vertebralfractures occur, the spine shortens further, increasingly forcing theindividual into a hunched-over posture.

As taught by U.S. Pat. No. 6,066,154 (Reiley et al.), which isincorporated herein by reference, it is known in the art to use aninflatable balloon-like device to treat certain bone conditions,resulting from osteoporosis, avascular necrosis, bone cancer and thelike, that predispose a bone to, or lead to, fracture or collapse. Aparticularly common application is in the treatment of vertebral bodycompression fractures resulting from osteoporosis.

Typical treatment of such conditions includes a series of steps which asurgeon or health care provider can perform to form a cavity in aninterior region of pathological bone, including but not limited toosteoporotic bone, osteoporotic fractured metaphyseal and epiphysealbone, osteoporotic vertebral bodies, fractured osteoporotic vertebralbodies, fractures of vertebral bodies due to tumors especially roundcell tumors, avascular necrosis of the epiphyses of long bones,especially avascular necrosis of the proximal femur, distal femur andproximal humerus and defects arising from endocrine conditions.

The method typically further includes the steps of making an incision inthe skin (usually one incision, but a second small incision may also berequired if a suction egress is used) followed by the placement of aguide pin which is passed through the soft tissue down to and into thebone.

The method of the Reiley '154 patent further includes the steps ofdrilling the bone to be treated to form a cavity or passage in the bone,following which an inflatable balloon-like device is inserted into thecavity or passage where it is inflated. The inflation of the inflatabledevice causes a compacting of the cancellous bone and bone marrowagainst the inner surface of the cortical wall of the bone to furtherenlarge the cavity or passage. The inflatable device is then deflatedand then is completely removed from the bone. The art further teachesthat a smaller inflatable device (a starter balloon) can be usedinitially, if needed, to initiate the compacting of the bone marrow andto commence the formation of the cavity or passage in the cancellousbone and marrow. After this has occurred, a larger, inflatable devicecan be inserted into the cavity or passage to further compact the bonemarrow in all directions.

At this point in accordance with Reiley '154, a flowable biocompatiblefilling material, such as methylmethacrylate cement or a synthetic bonesubstitute, is directed into the bone cavity or passage that has beenformed and enlarged, and the filling material is allowed to set to ahardened condition to provide ongoing structural support for the bone.Following this latter step, the insertion instruments are removed fromthe body and the incision in the skin is covered with a bandage.

A related U.S. Pat. No. 6,048,346 (Reiley et al.), which is alsoincorporated herein by reference, teaches an improved mechanical bonecement injection assembly, which is described as constituting animprovement over prior art devices that operated “similar to a householdcaulking gun” in that it facilitates greater control over the placementof cement and other flowable liquids into an interior region of a bone.

Another inflatable apparatus intended for deployment into interior bodyregions is described in U.S. Pat. No. 5,972,015 (Scribner et al.), whichis also incorporated herein by reference. The Scribner '015 patentdescribes a catheter tube extending along a first axis in conjunctionwith an expandable structure having an expanded geometry oriented abouta second axis, not aligned with the first axis, so as to treat anasymmetrically-shaped interior body region or where the access channelcannot be aligned with the body region to be treated. A particularapplication of this technology is stated to be for the fixation offractures or other osteoporotic and non-osteoporotic conditions of humanand animal bones, specifically for treating a human lumbar vertebra.

Two somewhat earlier patents describing similar apparatus and methodsfor treating vertebral body compression fractures and the like using aninflatable balloon-like element inserted into the bone cavity are U.S.Pat. Nos. 5,108,404 (Scholten et al.) and 4,969,888 (Scholten et al.),both of which are also incorporated herein by reference.

Numerous problems remain, however, with the prior art apparatuses andmethods. For successful expansion of a fractured vertebral body, anexpandable element inserted into the vertebral cavity must be capable ofbeing inflated to a relatively large working diameter of about 12 mm-25mm, starting with a relatively short balloon working length, e.g., about12 mm-25 mm, sized to fit inside the vertebral cavity, at very highworking pressures on the order of 200-400 psi or higher. It has beenfound that the use of lower inflation pressure in such applicationsresults in only a partial, incomplete expansion of the fracturedvertebral body. When that partially-expanded vertebral body issubsequently filled with cement or comparable material, which thenhardens, there is a permanent remaining spinal deformity at thatvertebral body. Not only must the expandable/inflatable element in thevertebral cavity be capable of inflation to very high pressure withoutpotentially disastrous rupture in order to fully expand acollapsed/fractured vertebral body, in addition the inflated elementmust resist puncture by hard, sharp cancellous bone and surfaceirregularities around the outer edges of the vertebral cavity. Standardmaterials commonly used in the prior art for constructing theexpandable, balloon-like element used to expand bone cavities cannot besafely inflated to very high pressures on the order of 200-400 psi orhigher, and, when inflated, typically do not have a high degree ofpuncture resistance.

One possible approach to improve the strength of the balloon-likeelements to make them better able to withstand very high inflationpressures would be to use thicker balloon walls and/or to make theseelements out of stiffer, stronger materials. There are several reasons,however, why these seemingly straightforward solutions have not provensuccessful in practice. One is the need to limit the balloon wallthickness and the need to maintain balloon wall flexibility tofacilitate access to, and withdrawal from, a bone cavity.

In treating a vertebral fracture, for example, the vertebral cavity istypically accessed by drilling a small hole and locating a short,hollow, metallic tubular element (canula) through the left or rightpedicle portion (or sometimes both) of the vertebral arch (see, e.g.,FIG. 2 of U.S. Pat. No. 5,972,015, which shows the left and rightpedicle portions 42 of vertebral arch 40, and FIG. 6 of the same patentwhich shows an access hole for catheter tube 50 and expandable structure56 through one pedicle portion 42 into the interior volume 30 ofreticulated cancellous, or spongy, bone 32). Because pedicle portion 42shown in FIGS. 2 and 6 of the Scribner '015 patent is relatively smalland is itself readily susceptible to fracture if its structuralintegrity is impaired by too large a hole, it is crucial to keep thediameter of the hole, therefore also of the canula, to a minimum,typically no larger than about 4-5 mm. The canula helps to protectsurrounding bone portions from abrasion and from expansion forces whileinserting or removing the catheter shaft or while inflating the balloonelement.

Thus, conventional practice has been to fold or wrap the balloon-likeelement relatively tightly around the end of a catheter shaft in orderto keep the maximum diameter of the unit at the balloon end small enoughto fit through the canula of a small-diameter pedicle hole. If aballoon-like expandable element was fabricated having relatively thickwalls and/or made from a relatively stiff, less flexible material, suchan element might well be inflatable to a higher pressure, but itgenerally could not be wound tightly enough about the distal end of acatheter shaft to fit through a narrow-diameter pedicle hole.

Even assuming that it were possible somehow to wrap a relativelythick-walled and/or stiff balloon element sufficiently tightly tofacilitate insertion of the device through a narrow-diameter pediclehole, it then would be virtually impossible using prior art technologyto remove or withdraw the balloon element through the same hole orcanula following dilatation. The reason is that, after a cycle ofinflation and deflation inside the vertebral cavity, athick-walled/relatively inflexible balloon element cannot be refolded orrewrapped in-situ to a sufficiently small diameter to be capable ofbeing withdrawn through the canula without the use of excessive forcewhich might crack or break the pedicle.

In another example, a balloon catheter according to the presentinvention can be used to treat congenital obstructions of the nasallacrimal duct. This procedure requires inserting an inflatable elementat the distal end of a catheter through the very narrow and sensitivelacrimal duct, inflating the balloon to compress the obstruction andopen the passageway, deflating the balloon, and thereafter removing thedeflated balloon element through the lacrimal duct. Following inflation,however, the balloon element may not return to its pre-inflation profilemaking withdrawal difficult.

These and other deficiencies in and limitations of the prior artapproaches to treating bone deformities, such as vertebral bodycompression fractures, and other medical treatments involving inserting,inflating, and thereafter deflating and removing a balloon elementthrough a relatively narrow body passageway are largely if notcompletely overcome with the apparatus and methods of this invention forbone, tissue and duct dilatation.

OBJECTS OF THE INVENTION

Accordingly, a general object of the present invention is to provideimproved apparatus and methods for bone, tissue and duct dilatation.

Another general object of the present invention is to provide improvedinflatable balloon-like elements for dilatation of interior boneregions, tissue portions, or duct segments in combination with balloonwithdrawal systems and methods of using the same.

Still another general object of the present invention is to provideinflatable balloon-like elements able to expand to relatively largediameters, to withstand relatively high inflation pressures, and toresist damage by hard, sharp cancellous bone for use in dilating aninterior region of a damaged bone.

A specific object of the present invention is to provide apparatus andmethods for more effectively treating vertebral body compressionfractures.

Another specific object of the present invention is to provide apparatusand methods for removing congenital obstructions of the nasal lacrimalduct.

Another specific object of the present invention is to provideinflatable balloon-like elements for dilatation of an interior region ofa damaged bone capable of expansion to inflated working diameters ofabout 12 mm-25 mm, starting with relatively short balloon workinglengths sized to fit inside a vertebral or other bone or body cavity, atworking pressures of about 200-400 psi or higher.

Still another specific object of the present invention is to provideinflatable balloon structures, capable of inflation to high workingpressures, which are relatively easily introduced into the interiorregion of a bone, tissue or duct through a small diameter opening, onthe order of about 4 to about 5 mm or less in diameter or width, andwhich balloon structures are capable of being collapsed to a very smalldiameter following inflation to facilitate withdrawal after use.

Yet another specific object of the present invention is to provideactive or passive balloon wrapping or tensioning assemblies, or both foruse in conjunction with inflatable balloon structures according to thepresent invention to facilitate insertion of a balloon structure througha narrow diameter opening or passageway and/or withdrawal of a balloonstructure through a narrow diameter opening or passageway following aninflation-deflation cycle.

Another specific object of the present invention is to provideassemblies comprising in combination an inflatable balloon element, acatheter shaft connected to the balloon element to provide a workingfluid for inflating the balloon element and for withdrawing the fluid todeflate the balloon element, and at least a balloon tensioning and/orwrapping device or both for stretching the balloon element and/orfolding, pleating or wrapping the balloon element to facilitateinsertion and/or removal of the balloon element through a narrowdiameter duct, access channel or canula typically having an opening ofabout 4 to 5 mm or less.

Other objects and advantages of the present invention will in part beobvious and will in part appear hereinafter. The invention accordinglycomprises, but is not limited to, the apparatus and related methods,involving the several steps and the various components, and the relationand order of one or more such steps and components with respect to eachof the others, as exemplified by the following description and theaccompanying drawings. Various modifications of and variations on theapparatus and methods as herein described will be apparent to thoseskilled in the art, and all such modifications and variations areconsidered within the scope of the invention.

SUMMARY OF THE INVENTION

The present invention provides for the fabrication, deployment,inflation, deflation and withdrawal of very high-pressure, puncture- andabrasion-resistant balloon catheters that are capable of beingrelatively easily introduced and withdrawn through a hole or canula inthe pedicle of a spine, or through the lacrimal duct, and in similarbody treatment applications. In other embodiments of the presentinvention, the balloons, expansion elements, and balloon cathetersdescribed herein function to increase the surface area of dilation inorder to more readily compress cancellus or other bone matter thereby toexpand a vertebral or other bone element, to compress or remove alacrimal duct obstruction, and in similar medical treatmentapplications.

Balloon catheter designs described herein provide for either active orpassive axial tension on the balloon or expansion element, or anassembly for wrapping the balloon element, or both. Tension and/orwrapping may be needed for both insertion and withdrawal, but has beenfound to be primarily needed for in-situ tensioning/wrapping prior towithdrawal where one does not have the benefit of being able to wrap theballoon down with one's fingers as is commonly done prior to insertion.

In accordance with the present invention, a balloon or expansion elementmay be mounted on the distal end of a hollow tube which may be eithermetal or plastic. These devices need not be flexible/bendable as iscommon with standard balloon catheters because the devices of thepresent invention typically are not intended to be snaked through thetortuous path of a blood vessel. The proximal end of the balloon isbonded to or integrally connected with the tube at or near the distalend of the tube to create a fluid passage through the tube to theinterior of the balloon element. The distal end of the balloon can beconfigured in several different ways.

In one embodiment, the distal end of the balloon is sealed off either byintegral manufacturing of a sealed end balloon, for example inaccordance with U.S. Pat. No. 5,411,477, which is incorporated herein byreference, or by sealing or potting the distal balloon neck. This end isleft unattached and an axially-oriented push rod is used to push againstthe sealed end of the balloon causing tension and axial elongation ormovement of the balloon during deflation, which causes the balloon toform a number of longitudinal pleats or folds which substantiallyreduces the profile of the deflated balloon allowing it to be moreeasily withdrawn. The fact that the distal end is not attached makesthis embodiment easier to manufacture and reduces the chance of a leakpoint by eliminating a glue or bond joint.

In an alternative embodiment, the distal end of the balloon can beattached to the push rod by adhesive or thermal bonding if desired. Thepush rod can be rotated and pushed to produce an even tighter re-wrap ofthe balloon. Both active and passive rotation of the push rod can beused.

The push rod can be spring loaded anywhere along the shaft, preferablyat the back (proximal) end of the catheter inside a suitable manifoldwhere the force, distance and other important parameters can be easilycontrolled, permanently set, or be made adjustable by the device user.The force can be active or passive, it can be adjusted so that there isalways an axial load on the balloon or only a load when the balloon isinflated and deflated. Once the balloon is stretched a predeterminedamount the tension is released. The removal of constant tension duringsterilization, storage, etc. can be important to prevent creep orweakening of the balloon and at the bond areas. A method of passivetension, but with an active preparation before using it, may be the mostdesirable approach for many applications.

The push rod itself can be a compressive spring or a spring can beincorporated anywhere along the length of the push rod or machined aspart of the rod. Alternatively, the design can be fabricated such thatthere is no push rod, but the hollow tube has a spring section eitherattached or integrally formed somewhere along its length inside theballoon, and the balloon is attached to this rod at one or both ends.The tension can also be provided by hydraulic or pneumatic actuation onthe back end of the device, or a pneumatic bladder can be inflated inthe back.

An adjustable position/tension rod may be preferred in some applicationsin which the balloon may be inflated to very high pressure beyond itselastic limit where permanent axial and radial deformation may occur.Such deformation would require the catheter design to accommodate thisgrowth to insure that enough tension and axial displacement takes placeto fold the balloon down.

In all of these designs, inflation of the balloon will cause the balloonto fill up in diameter while causing the overall length of the balloonto shorten, which will push or compress the shaft. The tension isdesigned to allow the balloon to fully expand. As the balloon isdeflated, the tension in the shaft pushes the distal end in the distaldirection and begins folding or collapsing the balloon and may alsoassist in more rapid deflation of the balloon. In another embodiment,elastomeric tubing can be placed over the balloon to help it refold andto protect the balloon from damage. The balloon can also be coated tohelp improve its puncture and abrasion resistance.

In still another embodiment of the present invention, a balloon that islonger than the length necessary to fill a bone or similar body cavitycan be used, and the canula can be designed so as to restrict anyexpansion thereby creating an absolute maximal dilation region for eachand every application without wasting space for the balloon transitionsor requiring multiple length balloons for treating various sizevertebral or other bone or body cavities. All that would be necessary isto have available several balloon diameters or a more compliant balloon,but of only one length. In this embodiment, it is also envisioned tosize or position the canula such that the distal end may extendpartially into the cavity to be dilated so as to further control balloonlength and area of dilation.

In still another embodiment, after dilating a balloon or inflationelement in accordance with this invention, the rod structure is removed,the balloon is filled with cement or a cement-like material that curesand hardens in situ and left in place as an implant. After removing thecanula, the long proximal neck can be cut off to separate the proximalend of the catheter from the filled balloon element. In anothervariation, a hollow push rod could be left in place during cementfilling of the balloon to act as a vent tube, which would be removedafter the balloon is full of cement.

In yet another embodiment of this invention, multi-lumen balloonelements, for example as described in my U.S. Pat. Nos. 5,342,301;5,569,195; and 5,624,392, which are incorporated herein by reference,may be used as the balloon elements for the catheters of this invention.

Other specific embodiments of the present invention include thefollowing:

(1) An assembly adapted for bone, tissue and/or duct dilatation of aliving being comprising in combination: a hollow tube; an inflatable anddeflatable balloon element having proximal and distal ends in fluidcommunication with the hollow tube; and, balloon tensioning and/orballoon wrapping device(s) for stretching the balloon element and/orfolding, pleating or wrapping the balloon element to facilitateinsertion and/or removal of the balloon element through a narrowdiameter duct, access channel or cannula.

(2) An assembly according to paragraph (1) above in which said balloonelement is capable of being inflated to a working diameter of about 12mm to about 25 mm.

(3) An assembly according to paragraph (1) above in which said balloonelement is capable of being inflated to a working pressure of about200-400 psi over a relatively short balloon working length.

(4) An assembly according to paragraph (1) above in which said balloonelement is stretched and/or folded, pleated or wrapped to a diameter ofabout 4-5 mm or less for insertion through and/or removal from saidduct, access channel or canula.

(5) An assembly according to paragraph (1) above in which said balloontensioning and/or balloon wrapping device(s) is/are selected from thegroup consisting of active and passive tensioning and wrapping devices.

(6) An assembly according to paragraph (1) above in which, uponinflation to its working pressure, the balloon element maintains a highdegree of puncture and abrasion resistance.

(7) An assembly according to paragraph (1) above in which the balloonelement is mounted on the distal end of the hollow tube, and theproximal end of the balloon element is bonded to or integrally connectedwith an end of the tube to create a passage through the tube to theinterior of the balloon element.

(8) An assembly according to paragraph (7) above in which the distal endof the balloon element is sealed, and the assembly further comprises arod element running through the passage of the tube and the interior ofthe balloon element to the sealed distal end of the balloon element.

(9) An assembly according to paragraph (8) above in which axial forcecan be applied manually or automatically to push the rod element againstthe sealed distal end of the balloon element causing tension and axialelongation of the balloon element.

(10) An assembly according to paragraph (9) above in which the rodelement is not attached to the balloon element.

(11) An assembly according to paragraph (9) above in which the rodelement is attached to or otherwise engages the balloon element.

(12) An assembly according to paragraph (11) above in which whereinrotational force can be applied manually or automatically to rotate therod element from its free-standing position causing the balloon elementat least in part to wrap around the rod element.

(13) An assembly according to paragraph (9) above in which wherein saidrod element is spring loaded to apply axial tensioning and elongation tothe balloon element.

(14) An assembly according to paragraph (11) above in which said rodelement is spring loaded to apply rotational tensioning to the balloonelement.

(15) An assembly according to paragraph (11) above in which said rodelement is spring loaded to apply both automatic axial and rotationaltensioning to the balloon element.

(16) An assembly according to paragraph (9) above in which said rodelement comprises a compressive or rotational spring element.

(17) An assembly according to paragraph (7) above in which said hollowtube comprises a compressive spring element.

(18) An assembly according to paragraph (1) above in which the balloontensioning and/or wrapping device is hydraulically or pneumaticallyactuated.

(19) An assembly according to paragraph (8) above in which said rodelement is adjustable in length.

(20) An assembly according to paragraph (1) above including elastomerictubing placed over said balloon element.

(21) An assembly according to paragraph (1) above in which wherein theexterior of said balloon element is coated with a material to improvepuncture and abrasion resistance.

(22) An assembly according to paragraph (11) above including at least acannula element wherein at least one end of the balloon element extendsinto or completely through said cannula element when the balloon elementis positioned in a cavity to be dilated.

(23) An assembly according to paragraph (22) above in which said cannulaelement is adapted to restrict expansion forces of the balloon elementduring inflation.

(24) An assembly according to paragraph (8) above in which, after theballoon element is inserted in a cavity to be dilated and inflated toworking pressure for a sufficient period of time, the interior of theinflated balloon element is filled in situ with a cement material.

(25) An assembly according to paragraph (24) above in which the rodelement is removed before the balloon element is filled with a cementmaterial.

(26) An assembly according to paragraph (24) above in which the rodelement has a hollow interior to act as a vent for working fluid whilethe balloon element is filled with a cement material, and is removedbefore the cement hardens.

(27) An assembly according to paragraph (24) above in which the hollowtube is detached from the balloon element after the balloon element isfilled with the cement material.

(28) An assembly according to paragraph (1) above in which said balloonelement comprises a multi-lumen balloon.

(29) An assembly according to paragraph (11) above in which said rodelement is spring loaded to apply automatic axial tensioning to theballoon element and is adapted for optional manual rotational tensioningof the balloon element.

(30) An assembly according to paragraph (1) above including a pre-curvedguidewire in the interior of the balloon element.

(31) An assembly according to paragraph (8) above in which said rodelement comprises concentric inner and outer tubular members which arerotatable relative to one another and said balloon element is attachedto or engages one of said tubular members whereby rotational forces canbe applied to cause the balloon element at least in part to wrap aroundone of said tubular members.

(32) An assembly according to paragraph (8) above in which wherein saidrod element is pre-curved and consists essentially of a material havingmemory properties.

(33) An assembly according to paragraph (1) above in which said balloonelement is pre-curved.

(34) An assembly according to paragraph (1) above in which said balloonelement consists essentially of a non-elastomeric material.

(35) A method for treating a living being for bone, tissue and/or bodyduct dilatation comprising the sequential steps of: inserting aninflatable balloon element in an uninflated state into an interiorregion, cavity or passage of a damaged, collapsed or deformed bone,tissue or duct through a first narrow diameter opening or passageway toposition the balloon element at a body location requiring dilatation;inflating the balloon element with a working fluid to a working pressureand for a time period sufficient to substantially completely dilate theinterior region, cavity or passage to substantially restore its normalsize, shape and/or alignment; deflating the balloon element bywithdrawing the working fluid; during and/or subsequent to saiddeflating step, stretching and/or folding, pleating or wrapping theballoon element to reduce its profile; and, withdrawing thepreviously-inflated balloon element through a narrow diameter opening orpassageway, which may be the same as or different than said first narrowdiameter opening or passageway.

(36) A method according to paragraph (35) above in which said balloonelement is inflated to a working diameter of about 12 mm to about 25 mmduring the inflating step.

(37) A method according to paragraph (35) above in which said balloonelement is inflated to a working pressure of about 200-400 psi over arelatively short balloon working length during the inflating step.

(38) A method according to paragraph (1) above in which said balloonelement is stretched and/or folded, pleated or wrapped to a diameter ofabout 4-5 mm or less for the steps of inserting and/or withdrawing theballoon element.

(39) A method according to paragraph (35) above in which said balloonelement is stretched and/or folded, pleated or wrapped using at least aballoon tensioning and/or balloon wrapping device selected from thegroup consisting of active and passive tensioning and wrapping devices.

(40) A method according to paragraph (35) above in which, followinginflation to its working pressure, the balloon element maintains a highdegree of puncture and abrasion resistance.

(41) A method according to paragraph (35) above including the step ofapplying a vacuum to the inflated balloon element during the deflatingstep to assist with withdrawal of the working fluid.

(42) A method according to paragraph (35) above in which the balloonelement is mounted on the distal end of a hollow tube, and the proximalend of the balloon element is bonded to or integrally connected with anend of the tube to create a passage through the tube to the interior ofthe balloon element.

(43) A method according to paragraph (42) above in which the distal endof the balloon element is sealed.

(44) A method according to paragraph (43) above in which a rod elementpasses through the tube and the interior of the balloon element to thesealed end of the balloon element.

(45) A method according to paragraph (44) above including the step ofapplying axial force manually or automatically to said sealed end of theballoon element through said rod element during and/or subsequent to thedeflating step causing tension and axial elongation of the balloonelement.

(46) A method according to paragraph (45) above in which the rod elementis not attached to the balloon element.

(47) A method according to paragraph (45) above in which the rod elementis attached to or otherwise engages the balloon element.

(48) A method according to paragraph (47) above including the step ofapplying rotational force manually or automatically to said rod elementduring and/or subsequent to the deflating step causing the balloonelement at least in part to wrap around the rod element.

(49) A method according to paragraph (45) above in which said rodelement is spring loaded to apply axial tensioning and elongation to theballoon element.

(50) A method according to paragraph (48) above in which said rodelement is spring loaded to apply rotational tensioning to the balloonelement.

(51) A method according to paragraph (35) above in which the balloontensioning and/or wrapping device is hydraulically or pneumaticallyactuated.

(52) A method according to paragraph (44) above in which said rodelement is adjustable in length, said method further comprising the stepof adjusting the length of said rod element such that said rod elementapplies an axial tensioning to the balloon element during the deflatingstep.

(53) A method according to paragraph (35) above including the step ofcoating the exterior of the balloon element with a coating to improvepuncture and abrasion resistance.

(54) A method according to paragraph (35) above in which, upon insertingthe balloon element into an interior region, cavity or passage, at leastone end of the balloon element extends into or completely through acannula element positioned in one of the narrow diameter openings orpassageways.

(55) A method according to paragraph (35) above in which said balloonelement comprises a multi-lumen balloon.

(56) A method according to paragraph (47) above in which said rodelement is spring loaded to automatically apply axial tensioning to theballoon element during the deflating step, said method furthercomprising the step of applying manual rotational tensioning to theballoon element during and/or subsequent to the deflating step.

(57) A method according to paragraph (35) above including the steps ofpositioning a guidewire through the interior region, cavity or passageto be dilated, and using the guidewire to position the balloon elementduring the inserting step.

(58) A method according to paragraph (57) above in which said guidewireis pre-curved.

(59) A method according to paragraph (44) above in which said rodelement is pre-curved and fabricated from a material having memoryproperties.

(60) A method according to paragraph (35) above in which said balloonelement is pre-curved.

(61) A method according to paragraph (35) above in which said balloonelement consists essentially of a non-elastomeric material.

(62) A method for treating a living being for bone or tissue dilatationcomprising the sequential steps of: providing a dilatation apparatusable to fit through a narrow opening, said dilatation apparatuscomprising an inflatable balloon element in fluid communication with ahollow tube, and a rod element running through the interior of thehollow tube and the inflatable balloon element, wherein said balloonelement is uninflated and is wrapped, folded, pleated or stretched atleast in part about said rod element to reduce the profile of theballoon portion of the dilatation apparatus; inserting the dilatationapparatus into an interior region, cavity or passage of a damaged,collapsed or deformed bone or tissue region through a first narrowdiameter opening or passageway to position the balloon element at a bodylocation requiring dilatation; inflating the balloon element through thehollow tube with a working fluid to a working pressure and for a timeperiod sufficient to substantially completely dilate the interiorregion, cavity or passage to substantially its normal size, shape and/oralignment; and, filling the inflated balloon element in situ through thehollow tube with a cement material.

(63) A method according to paragraph (62) above including the furthersteps of removing the rod element before filling the balloon elementwith cement material and detaching the hollow tube from the balloonelement after it is filled with cement.

(64) A method according to paragraph (62) above in which the rod elementhas a hollow interior which is used for venting working fluid from theballoon element while it is being filled with cement material.

(65) A method according to paragraph (64) above including the steps ofremoving the rod element and detaching the hollow tube from the balloonelement after it is filled with cement.

(66) A method according to paragraph (62) above in which said balloonelement is inflated to a working diameter of about 12 mm to about 25 mmduring the inflating step.

(67) A method according to paragraph (62) above in which said balloonelement is inflated to a working pressure of about 200-400 psi over arelatively short balloon working length during the inflating step.

(68) A method according to paragraph (62) above in which said balloonelement is wrapped, folded, stretched and/or pleated about said rodelement such that the balloon portion of the dilatation apparatus has adiameter of about 4-5 mm or less for the inserting step.

(69) A method according to paragraph (62) above in which said balloonelement comprises a multi-lumen balloon.

(70) A method according to paragraph (62) above including the steps ofpositioning a guidewire through the interior region, cavity or passageto be dilated, and using the guidewire to position the balloon elementduring the inserting step.

(71) A method according to paragraph (62) above in which said guidewireis pre-curved.

(72) A method according to paragraph (62) above in which said rodelement is pre-curved and fabricated from a material having memoryproperties.

(73) A method according to paragraph (62) above in which said rodelement is pre-curved and fabricated from a material having memoryproperties.

(74) A method according to paragraph (62) above in which said balloonelement consists essentially of a non-elastomeric material.

(75) A method for treating a living being for dilatation of a section ofa body duct to relieve a collapse or blockage condition comprising thesequential steps of: providing a dilatation apparatus able to fitthrough a narrow opening, said dilatation apparatus comprising aninflatable balloon element in fluid communication with a hollow tube,and a rod element running through the interior of the hollow tube andthe inflatable balloon element, wherein said balloon element isuninflated and is wrapped, folded, pleated or stretched at least in partabout said rod element to reduce the profile of the balloon portion ofthe dilatation apparatus; inserting the dilatation apparatus into a bodyduct to be dilated to position the balloon element at a duct sectionrequiring dilatation; inflating the balloon element through the hollowtube with a working fluid to a working pressure and for a time periodsufficient to substantially completely dilate the duct section tosubstantially its normal size; deflating the balloon element bywithdrawing the working fluid; during and/or subsequent to saiddeflating step, stretching and/or folding, pleating or wrapping theballoon element to reduce its profile; and, withdrawing the dilatationapparatus including the previously-inflated balloon element from thetreated duct.

(76) A method according to paragraph (75) above in which said balloonelement is inflated to a working diameter of about 12 mm to about 25 mmduring the inflating step.

(77) A method according to paragraph (75) above in which said balloonelement is inflated to a working pressure of about 200-400 psi over arelatively short balloon working length during the inflating step.

(78) A method according to paragraph (75) above in which said balloonelement is stretched and/or folded, pleated or wrapped to a diameter ofabout 4-5 mm or less for the steps of inserting and/or withdrawing theballoon element.

(79) A method according to paragraph (75) above in which said balloonelement is stretched and/or folded, pleated or wrapped using at least aballoon tensioning and/or balloon wrapping device selected from thegroup consisting of active and passive tensioning and wrapping devices.

(80) A method according to paragraph (75) above including the step ofapplying a vacuum to the inflated balloon element during the deflatingstep to assist with withdrawal of the working fluid.

(81) A method according to paragraph (75) above in which the distal endof the balloon element is sealed, said method further comprising thestep of applying axial force manually or automatically to said sealedend of the balloon element through said rod element during and/orsubsequent to the deflating step causing tension and axial elongation ofthe balloon element.

(82) A method according to paragraph (81) above in which the rod elementis not attached to the balloon element.

(83) A method according to paragraph (81) above in which the rod elementis attached to or otherwise engages the balloon element.

(84) A method according to paragraph (83) above including the step ofapplying rotational force manually or automatically to said rod elementduring and/or subsequent to the deflating step causing the balloonelement at least in part to wrap around the rod element.

(85) A method according to paragraph (81) above in which said rodelement is spring loaded to apply axial tensioning and elongation to theballoon element.

(86) A method according to paragraph (84) above in which said rodelement is spring loaded to apply rotational tensioning to the balloonelement.

(87) A method according to paragraph (75) above in which the balloontensioning and/or wrapping device is hydraulically or pneumaticallyactuated.

(88) A method according to paragraph (75) above in which said rodelement is adjustable in length, said method further comprising the stepof adjusting the length of said rod element such that said rod elementapplies an axial tensioning to the balloon element during the deflatingstep.

(89) A method according to paragraph (84) above in which said rodelement is spring loaded to automatically apply axial tensioning to theballoon element during the deflating step, said method furthercomprising the step of applying manual rotational tensioning to theballoon element during and/or subsequent to the deflating step.

(90) A method according to paragraph (75) above in which said rodelement comprises concentric inner and outer tubular members which arerotatable relative to one another, and said balloon element is attachedto or engages one of said tubular members, said method furthercomprising the step of rotating said tubular members relative to oneanother during an/or subsequent to the deflating step to cause theballoon element to wrap at least in part around one of said tubularmembers.

These and other variations and embodiments of the apparatus of thisinvention, and different applications for and methods of using suchapparatus, will be apparent from the drawings and the followingdescription of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic elevation view of apparatus according to a firstembodiment of the present invention designed for automatic tensioning ofa balloon element using a spring tensioning system located at theproximal (external) end of the device to facilitate withdrawal through asmall diameter canula from a bone cavity following dilatation andsubsequent deflation. In FIG. 1A, the catheter is shown in a neutralposition as it would be for shipping and storage prior to use. The capportion is loose, and there is no compression of the spring element. Theballoon element is shown extended, pleated and/or folded forcompactness.

FIG. 1C is an end view of the apparatus of FIG. 1A as seen from thedistal end.

FIG. 1B is a cross-sectional view of the device as shown in FIG. 1Ctaken along line 1B-1B.

FIG. 2A is a schematic elevation view of the same apparatus shown inFIG. 1A, except that in FIG. 2A the cap has been screwed down resultingin at least partially compressing the spring element in preparation forusing the device. The balloon element remains extended and folded and/orpleated.

FIG. 2C is an end view of the apparatus of FIG. 2A as seen from thedistal end.

FIG. 2B is a cross-sectional view of the device as shown in FIG. 2Ctaken along line 2B-2B.

FIG. 3A is a schematic elevation view of the same apparatus shown inFIGS. 1A and 2A, except that in FIG. 3A pressurized fluid has beenintroduced to fully inflate the balloon element. As a consequence of theballoon being inflated, it expands in diameter and shortens in lengthcausing the rod/disc elements to be displaced toward the proximal end ofthe apparatus thereby further compressing the spring element.

FIG. 3C is an end view of the apparatus of FIG. 3A as seen from thedistal end.

FIG. 3B is a cross-sectional view of the device as shown in FIG. 3Ctaken along line 3B-3B.

FIG. 4A is a schematic elevation view of the same apparatus shown inFIGS. 1A, 2A and 3A, except that in FIG. 4A dilatation pressure has beenremoved and, optionally, a vacuum may be applied to the fluidinlet/outlet conduit to withdraw fluid from the formerly inflatedballoon element thereby collapsing it. As the balloon element isdeflated, the compressed spring element exerts a force on the disc androd pushing them axially toward the distal end of the apparatus. Thisresults in stretching and tensioning the balloon element therebyassisting in collapsing, folding and/or pleating the balloon element foreasier withdrawal from the dilated bone cavity.

FIG. 4C is an end view of the apparatus of FIG. 4A as seen from thedistal end.

FIG. 4B is a cross-sectional view of the device as shown in FIG. 4Ctaken along line 4B-4B.

FIG. 5A is a schematic elevation view of apparatus according to a secondembodiment of the present invention designed for manual tensioning andoptional rotation (twisting and wrapping) of a balloon element tofacilitate withdrawal through a small diameter canula from a bone cavityfollowing dilatation and subsequent deflation. In FIG. 5A, the catheteris shown in a neutral position as it would be for shipping and storageprior to use. The cap is loose, the balloon element is prefolded and/orpleated, and, optionally, wrapped around a push rod extending along thelongitudinal axis of the device. The sealing gasket is not compressed,and the push rod is in a forward position (toward the distal end of thedevice). In one variation of this embodiment of the invention, the pushrod may be attached to the distal tip of the balloon element orotherwise capable of engaging the balloon element to enable twisting theballoon element to wrap it around the push rod as described furtherbelow.

FIG. 5C is an end view of the apparatus of FIG. 5A as seen from thedistal end.

FIG. 5B is a cross-sectional view of the device as shown in FIG. 5Ctaken along line 5B-5B.

FIG. 6A is a schematic elevation view of the same apparatus shown inFIG. 5A, except that in FIG. 6A the cap has been tightened and thesealing gasket compressed in preparation for use to prevent pressurizedinflation fluid from leaking out of the proximal end of the device.

FIG. 6C is an end view of the apparatus of FIG. 6A as seen from thedistal end.

FIG. 6B is a cross-sectional view of the device as shown in FIG. 6Ctaken along line 6B-6B.

FIG. 7A is a schematic elevation view of the same apparatus shown inFIGS. 5A and 6A, except that in FIG. 7A pressurized fluid has been usedto fully inflate the balloon element. As a consequence of the balloonbeing inflated, it expands in diameter and shortens in length causingthe push rod to be displaced toward the proximal end of the apparatus.

FIG. 7C is an end view of the apparatus of FIG. 7A as seen from thedistal end.

FIG. 7B is a cross-sectional view of the device as shown in FIG. 7Ctaken along line 7B-7B.

FIG. 8A is a schematic elevation view of the same apparatus shown inFIGS. 5A, 6A and 7A, except that in FIG. 8A dilatation pressure has beenremoved and, optionally, a vacuum may be applied to the fluidinlet/outlet conduit to withdraw fluid from the formerly inflatedballoon element thereby collapsing it. As the balloon is being deflated,or after deflation, axial force is manually applied to the proximal endof the push rod to push it toward the distal end of the device therebyassisting with stretching and refolding or repleating the balloon foreasier withdrawal through the canula from a dilated bone cavity.

FIG. 8C is an end view of the apparatus of FIG. 8A as seen from thedistal end.

FIG. 8B is a cross-sectional view of the device as shown in FIG. 8Ctaken along line 8B-8B.

FIG. 9A is a schematic elevation view of the same apparatus shown inFIGS. 5A, 6A and 7A, except that in FIG. 9A the push rod is attached toor engages the balloon and, as the formerly inflated balloon is beingdeflated, or after deflation, rotational force is manually applied tothe proximal end of the push rod to rotate the push rod resulting inwrapping the deflated balloon around the push rod to further reduce theballoon profile for easier withdrawal through the canula from a dilatedbone cavity.

FIG. 9C is an end view of the apparatus of FIG. 9A as seen from thedistal end.

FIG. 9B is a cross-sectional view of the device as shown in FIG. 9Ctaken along line 9B-9B.

FIG. 10A is a schematic elevation view of apparatus according to a thirdembodiment of the present invention designed for automatic tensioning ofa balloon element to facilitate withdrawal through a small diametercanula from a bone cavity following dilatation and subsequent deflation.The apparatus of FIG. 10A is configured substantially similar to thatshown in FIG. 1A except that the inflation/deflation port in FIG. 10Ahas been integrated into the cap/proximal end structure therebyeliminating the Y-element or side branch in FIG. 1A which served as thefluid inlet/outlet conduit.

FIG. 10C is an end view of the apparatus of FIG. 10A as seen from thedistal end.

FIG. 10B is a cross-sectional view of the device as shown in FIG. 10Ctaken along line 10B-10B.

FIG. 11A is a schematic elevation view of the same apparatus shown inFIG. 10A, except that in FIG. 11A the cap has been screwed down andpressurized fluid has been introduced to fully inflate the balloonelement. As a consequence of screwing down the cap and inflating theballoon, the spring element has been compressed.

FIG. 11C is an end view of the apparatus of FIG. 11A as seen from thedistal end.

FIG. 11B is a cross-sectional view of the device as shown in FIG. 11Ctaken along line 11B-11B.

FIG. 12A is a schematic elevation view of the same apparatus shown inFIGS. 10A and 11A, except that in FIG. 12A dilatation pressure has beenremoved and, optionally, a vacuum may be applied to theinflation/deflation port to withdraw fluid from the formerly inflatedballoon element thereby collapsing it. As the balloon element isdeflated, the compressed spring element exerts a force on the disc androd pushing them axially toward the distal end of the apparatus. Thisresults in stretching and tensioning the balloon element therebyassisting in collapsing, folding and/or pleating the balloon element foreasier withdrawal from the dilated bone cavity.

FIG. 12C is an end view of the apparatus of FIG. 12A as seen from thedistal end.

FIG. 12B is a cross-sectional view of the device as shown in FIG. 12Ctaken along line 12B-12B.

FIG. 13A is a schematic elevation view of apparatus according to afourth embodiment of the present invention for automatic tensioning ofan adjustable length balloon element to facilitate withdrawal through asmall diameter canula from a bone cavity following dilatation andsubsequent deflation. In this embodiment, the balloon element isdesigned longer than necessary to fill the bone cavity being treated,and an adjustable clamp, nut, collar or similar element is used to helpmaintain a precise balloon length and to resist expansion forces duringballoon inflation. The apparatus of FIG. 13A is otherwise shownconfigured substantially similar to that of FIG. 1A with cap and springelements to effect automatic tensioning of the balloon element upondeflation. In FIG. 13A, the cap portion is loose, and there is nocompression of the spring element.

FIG. 13C is an end view of the apparatus of FIG. 13A as seen from thedistal end.

FIG. 13B is a cross-sectional view of the device as shown in FIG. 13Ctaken along line 13B-13B.

FIG. 14A is a schematic elevation view of the same apparatus shown inFIG. 13A, except that in FIG. 14A the cap has been screwed downresulting in at least partially compressing the spring element inpreparation for using the device. The balloon element remains extendedand folded and/or pleated.

FIG. 14C is an end view of the apparatus of FIG. 14A as seen from thedistal end.

FIG. 14B is a cross-sectional view of the device as shown in FIG. 14Ctaken along line 14B-14B.

FIG. 15A is a schematic elevation view of the same apparatus shown inFIGS. 13A and 14A, except that in FIG. 15A pressurized fluid has beenintroduced to inflate the distal end balloon element. As a consequenceof the balloon being inflated, inflation forces try to push the canulabackward (toward the proximal end) and/or to pull the catheter out. Theadjustable nut or comparable element prevents such undesirablemovements.

FIG. 15C is an end view of the apparatus of FIG. 15A as seen from thedistal end.

FIG. 15B is a cross-sectional view of the device as shown in FIG. 15Ctaken along line 15B-15B.

FIG. 16A is a schematic elevation view of the same apparatus shown inFIGS. 13A, 14A and 15A, except that in FIG. 16A dilatation pressure hasbeen removed and, optionally, a vacuum may be applied to the fluidinlet/outlet conduit to withdraw fluid from the formerly inflatedballoon element thereby collapsing it. As the balloon element isdeflated, the compressed spring element exerts a force on the disc androd pushing them axially toward the distal end of the apparatus. Thisresults in stretching and tensioning the balloon element therebyassisting in collapsing, folding and/or pleating the balloon element foreasier withdrawal from the dilated bone cavity.

FIG. 16C is an end view of the apparatus of FIG. 16A as seen from thedistal end.

FIG. 16B is a cross-sectional view of the device as shown in FIG. 16Ctaken along line 16B-16B.

FIG. 17A is a schematic elevation view of apparatus according to a fifthembodiment of the present invention designed for automatic tensioningand optional manual rotation (twisting and wrapping) of a balloonelement to facilitate withdrawal through a small diameter canula from abone cavity following dilatation and subsequent deflation. In thisconfiguration, the rod passes through the disc and is attached to thedisc and to the balloon element. In FIG. 17A, the catheter is shown in aneutral position as it would be for shipping and storage prior to use.The cap portion is loose, and there is no compression of the springelement. The balloon element is shown extended, pleated and/or foldedfor compactness.

FIG. 17C is an end view of the apparatus of FIG. 17A as seen from thedistal end.

FIG. 17B is a cross-sectional view of the device as shown in FIG. 17Ctaken along line 17B-17B.

FIG. 18A is a schematic elevation view of the same apparatus shown inFIG. 17A, except that in FIG. 18A the cap has been screwed downresulting in at least partially compressing the spring element inpreparation for using the device. The balloon element remains extendedand folded and/or pleated.

FIG. 18C is an end view of the apparatus of FIG. 18A as seen from thedistal end.

FIG. 18B is a cross-sectional view of the device as shown in FIG. 18Ctaken along line 18B-18B.

FIG. 19A is a schematic elevation view of the same apparatus shown inFIGS. 17A and 18A, except that in FIG. 19A pressurized fluid has beenintroduced to fully inflate the balloon element. As a consequence of theballoon being inflated, it expands in diameter and shortens in lengthcausing the rod/disc elements to be displaced toward the proximal end ofthe apparatus thereby further compressing the spring element.

FIG. 19C is an end view of the apparatus of FIG. 19A as seen from thedistal end.

FIG. 19B is a cross-sectional view of the device as shown in FIG. 19Ctaken along line 19B-19B.

FIG. 20A is a schematic elevation view of the same apparatus shown inFIGS. 17A, 18A and 19A, except that in FIG. 20A dilatation pressure hasbeen removed and, optionally, a vacuum may be applied to the fluidinlet/outlet conduit to withdraw fluid from the formerly inflatedballoon element thereby collapsing it. As the balloon element isdeflated, the compressed spring element exerts a force on the disc androd pushing them axially toward the distal end of the apparatus. Thisresults in stretching and tensioning the balloon element therebyassisting in collapsing, folding and/or pleating the balloon element foreasier withdrawal from the dilated bone cavity.

FIG. 20C is an end view of the apparatus of FIG. 20A as seen from thedistal end.

FIG. 20B is a cross-sectional view of the device as shown in FIG. 20Ctaken along line 20B-20B.

FIG. 21A is a schematic elevation view of the same apparatus shown inFIGS. 17A, 18A, 19A and 20A, except that in FIG. 21A the rod is attachedto or engages the balloon and, as the formerly inflated balloon is beingdeflated, or after deflation, rotational force is manually applied tothe proximal end of the rod to rotate the rod resulting in wrapping thedeflated balloon around the rod to further reduce the balloon profilefor easier withdrawal through the canula from a dilated bone cavity.

FIG. 21C is an end view of the apparatus of FIG. 21A as seen from thedistal end.

FIG. 21B is a cross-sectional view of the device as shown in FIG. 21Ctaken along line 21B-21B.

FIG. 22A is a schematic elevation view of apparatus according to a sixthembodiment of the present invention designed for automatic tensioning ofa balloon element using a spring tensioning system located at the distal(internal) end of the device to facilitate withdrawal through a smalldiameter canula from a bone cavity following dilatation and subsequentdeflation. In FIG. 22A, the catheter is shown in a neutral position asit would be for shipping and storage prior to use. The cap portion isloose, and there is little or no compression of the spring element. Theballoon element is shown extended, pleated and/or folded forcompactness.

FIG. 22C is an end view of the apparatus of FIG. 22A as seen from thedistal end.

FIG. 22B is a cross-sectional view of the device as shown in FIG. 22Ctaken along line 22B-22B.

FIG. 22D is an enlarged cross-sectional view of the distal end of thedevice as shown in FIG. 22B to better illustrate details of the springtensioning system at the balloon end of the apparatus.

FIG. 23A is a schematic elevation view of the same apparatus shown inFIG. 22A, except that in FIG. 23A the cap has been screwed downresulting in at least partially compressing the spring element andapplying axial tension to the balloon in preparation for using thedevice. The balloon element remains extended and folded and/or pleated.

FIG. 23C is an end view of the apparatus of FIG. 23A as seen from thedistal end.

FIG. 23B is a cross-sectional view of the device as shown in FIG. 23Ctaken along line 23B-23B.

FIG. 23D is an enlarged cross-sectional view of the distal end of thedevice as shown in FIG. 23B to better illustrate details of the springtensioning system at the balloon end of the apparatus.

FIG. 24A is a schematic elevation view of the same apparatus shown inFIGS. 22A and 23A, except that in FIG. 24A pressurized fluid has beenintroduced to fully inflate the balloon element. As a consequence of theballoon being inflated, it expands in diameter and shortens in lengththereby further compressing the spring element.

FIG. 24C is an end view of the apparatus of FIG. 24A as seen from thedistal end.

FIG. 24B is a cross-sectional view of the device as shown in FIG. 24Ctaken along line 24B-24B.

FIG. 24D is an enlarged cross-sectional view of the distal end of thedevice as shown in FIG. 24B to better illustrate details of the springtensioning system at the balloon end of the apparatus.

FIG. 25A is a schematic elevation view of the same apparatus shown inFIGS. 22A, 23A and 24A, except that in FIG. 25A dilatation pressure hasbeen removed and, optionally, a vacuum may be applied to the fluidinlet/outlet conduit to withdraw fluid from the formerly inflatedballoon element thereby collapsing it. As the balloon element isdeflated, the compressed spring element exerts a force on the rodpushing it axially toward the distal end of the apparatus. This resultsin stretching and tensioning the balloon element thereby assisting incollapsing, folding and/or pleating the balloon element for easierwithdrawal from the dilated bone cavity.

FIG. 25C is an end view of the apparatus of FIG. 25A as seen from thedistal end.

FIG. 25B is a cross-sectional view of the device as shown in FIG. 25Ctaken along line 25B-25B.

FIG. 25D is an enlarged cross-sectional view of the distal end of thedevice as shown in FIG. 25B to better illustrate details of the springtensioning system at the balloon end of the apparatus.

Similar to the embodiments of FIGS. 5-9 and 17-21, the embodiment ofFIGS. 22-25 can readily be adapted to add a rod rotation/balloonwrapping capability if the rod is equipped with a rotation-resistingelement and the rod engages or can engage the end of the balloon.

FIGS. 26A-26D show schematic cross-sectional views of a vertebralsegment with a V-shaped catheter access channel formed through bothpedicle portions and the cancellous bone being treated in accordancewith one embodiment of the present invention.

FIGS. 27A-27D show schematic cross-sectional views of a vertebralsegment with a V-shaped catheter access channel formed through bothpedicle portions and the cancellous bone being treated in accordancewith another embodiment of the present invention.

FIGS. 28A-28E show schematic cross-sectional views of a vertebralsegment with a U-shaped catheter access channel formed through bothpedicle portions and the cancellous bone being treated in accordancewith still another embodiment of the present invention.

FIG. 29 shows a schematic cross-sectional view of a vertebral segmentwith a U-shaped catheter access channel formed through both pedicleportions and the cancellous bone being treated in accordance with stillanother embodiment of the present invention.

FIG. 30 shows a schematic cross-sectional view of a vertebral segmentwith a U-shaped catheter access channel formed through both pedicleportions and the cancellous bone being treated with a catheter apparatususing a pre-curved guidewire in accordance with another embodiment ofthe present invention.

FIG. 31 is a schematic side view of a pre-curved balloon elementdesigned for use in some embodiments of the present invention.

FIG. 32 is a schematic cross-sectional view of a vertebral segment witha catheter access channel formed through only one pedicle portion beingtreated with a catheter apparatus using a pre-curved guidewire inaccordance with another embodiment of the present invention.

FIG. 33 is a schematic cross-sectional view of a vertebral segment withcatheter access channels formed through both pedicle portions fortreatment with two catheter apparatuses in accordance with still anotherembodiment of the present invention.

FIG. 34A is a schematic elevation view of apparatus according to stillanother embodiment of the present invention designed for wrapping aballoon or inflation element to facilitate withdrawal through a smalldiameter canula from a bone cavity or through a small diameter ductfollowing dilatation and subsequent deflation. The apparatus of FIG. 34Ais configured somewhat similar to that shown in FIG. 10A except that inFIG. 34A there is a fixed inner shaft and the balloon is wrapped byrotating the outer shaft. This can be accomplished with or withouttensioning of the balloon or inflation element.

FIG. 34C is an end view of the apparatus of FIG. 34A as seen from thedistal end.

FIG. 34B is a cross-sectional view of the device as shown in FIG. 34Ctaken along line 34B-34B.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1-4 illustrate a dilatation balloon tensioning apparatus accordingto a first embodiment of the present invention. The balloon dilatationcatheter apparatus 10 in FIGS. 1A-1C generally comprises a proximal endcatheter sleeve portion 12, a middle sleeve portion 14, and a balloon orinflation element 16 at or near the distal end of the catheter. As bestseen in FIG. 1B, proximal end catheter sleeve portion 12 comprises abranched or Y-shaped element, of which one arm or branch 18 comprises atubular shell with external threads 25 at its proximal end, and thesecond arm or branch 20 comprises a fluid inlet/outlet conduit forintroducing pressurized fluid 40 into catheter 10 for inflating balloon16 or for withdrawing fluid 40 after a dilatation procedure.

The tubular shell of branch 18 comprises a region adjacent to thethreaded region for housing a spring element 22. Cap element 24 hasinternal threads and is sized to mate with the external threads 25 atthe proximal end of branch 18. As seen in FIGS. 1A-1C, the cap element24 is loosely threaded onto branch 18, and there is no compression ofspring element 22, the condition in which catheter 10 would ordinarilybe shipped and stored. Balloon element 16 is shown extended, and, asseen in FIGS. 1A and 1C, is preferably pleated or folded forcompactness.

Balloon elements suitable for use with the various catheter designsdescribed herein may be elastomeric or non-elastomeric, depending on theparticular application, and may be fabricated from various conventionalballoon catheter materials, for example the various catheter and balloonmaterials taught by U.S. Pat. No. 5,499,973, which is incorporatedherein by reference. It is also within the scope of this invention tocoat the exterior of the balloon elements to prevent or minimize damageor rupture from sharp bones. It is also within the scope of thisinvention to cover the balloon elements with elastomeric tubes both tohelp squeeze and deflate the balloons during deflation and to resistdamage from surrounding bone.

At the distal end of the region for housing spring element 22 (i.e., atthe end opposite from where the cap 24 is threaded onto branch 18), adisc element or circular fitting 30 is sized to slide inside the regionhousing spring element 22 so as to compress the spring element bydisplacement in the proximal direction or to decompress the springelement by displacement in the distal direction. Associated with discelement 30 is axially moveable rod element 34 (which may or may not bephysically connected to disc element 30) which runs axially through theinterior of the catheter from the distal side of disc element 30 to thesealed tip portion 28 of balloon 16. Rod element 34 may or may not bephysically connected to or may or may not engage balloon tip portion 28.Rod element 34 operating in conjunction with disc element 30 thus canact like a piston to alternately compress and allow decompression ofspring element 22.

Also shown in FIGS. 1A-1C, although it is typically not attached tocatheter apparatus 10, is a small diameter canula 26 which provides achannel for the catheter apparatus through a bone portion into the boneinterior. Balloon element 16 must be able to slide through the hollowinterior of canula 26 during insertion of the catheter and, moreimportantly, during removal of the catheter after the balloon hasundergone an inflation/deflation cycle.

In FIGS. 2A-2C, catheter apparatus 10 of FIGS. 1A-1C is shown with capelement 24 screwed down resulting in at least partially compressingspring element 22 in preparation for use. In FIGS. 3A-3C, pressurizedfluid 40 has been introduced through branch 20, through a part of theinterior of proximal sleeve portion 12, and through the interior ofmiddle sleeve portion 14 to fully inflate balloon 16. As balloon 16 isinflated, it expands in diameter and shortens in length causing rod 34to move in a proximal direction, thereby displacing disc element 30 in aproximal direction and further compressing spring element 22.

In FIGS. 4A-4C, dilatation pressure is removed and fluid is withdrawnfrom balloon 16 and from the interior of catheter 10 through fluidinlet/outlet branch 20. In a preferred embodiment, a vacuum may beapplied to the proximal end of branch 20 to assist in withdrawing fluidand fully collapsing balloon 16. As balloon 16 becomes deflated, theforce exerted by the compressed spring element 22 becomes greater thanthe force exerted by the collapsing balloon. Eventually this results indisplacing disc element 30 toward the distal end of the catheter, inturn driving rod 34 in the distal direction, and thereby stretching andtensioning balloon 16. This automatic tensioning of the balloon elementupon deflation assists in collapsing, folding and/or pleating theballoon to minimize its lateral profile for easier withdrawal throughthe small diameter interior channel of canula 26.

FIGS. 5-9 illustrate a dilatation balloon tensioning apparatus accordingto a second embodiment of the present invention. The balloon dilatationcatheter apparatus 110 in FIGS. 5A-5C generally comprises a proximal endcatheter sleeve portion 112, a middle sleeve portion 114, and a balloonor inflation element 116 at the distal end of the catheter. As best seenin FIG. 5B, proximal end catheter sleeve portion 112 comprises abranched or Y-shaped element, of which one arm or branch 118 comprises atubular shell with external threads 125 at its proximal end, and thesecond arm or branch 120 comprises a fluid inlet/outlet conduit forintroducing pressurized fluid 140 into catheter 110 for inflatingballoon 116 or for withdrawing fluid 140 after a dilatation procedure.

The tubular shell of branch 118 comprises a region adjacent to thethreaded region for housing a sealing gasket 122 or similar compressiblesealing element having a centrally located aperture. Cap element 124includes a centrally-located axial bore 127 to accommodate a push rod134, and also has internal threads sized to mate with the externalthreads 125 at the proximal end of branch 118. As seen in FIGS. 5A-5C,cap element 124 is loosely threaded onto branch 118, rod 134 is forward(toward the distal end of the catheter), and there is no compression ofsealing gasket 121, the condition in which catheter 110 would ordinarilybe shipped and stored. Balloon element 116 is shown extended, as bestseen in FIG. 5C, and is preferably pleated or folded for compactness.

Push rod 134, having a knob portion 136 at its proximal end, is slidablypositioned inside the catheter and is sized to extend axially the fulllength of catheter 110. Push rod 134 extends through the central bore127 of cap 124, through the sealing gasket 121, which acts like abushing for supporting and centering rod 134, through the interior ofsleeves 112 and 114, and through the interior of balloon 116 to thesealed tip portion 128. In one variation of this invention embodiment,rod 134 may be connected to or capable of engaging tip portion 128 tofacilitate twisting or wrapping balloon element 116 about rod 134following a dilatation and deflation cycle.

In FIGS. 6A-6C, catheter apparatus 110 of FIGS. 5A-5C is shown with capelement 124 screwed down and tightened thereby compressing sealinggasket 121 to form a fluid-tight seal at the sealing gasket and aroundrod 134 in preparation for using the catheter, while still permittingrod 134 to slide through the gasket aperture. In FIGS. 7A-7C,pressurized fluid 140 has been introduced through branch 120 to fullyinflate balloon 116. As balloon 116 is inflated, it expands in diameterand shortens in length causing rod 134 to slide in a proximal direction.

In FIGS. 8A-8C, dilatation pressure is removed and fluid is withdrawnfrom balloon 116 and from the interior of catheter 110 through branch120. In a preferred embodiment, a vacuum may be applied to the proximalend of branch 20 to assist in withdrawing fluid and in fully collapsingballoon 116. As balloon 116 becomes deflated, axial force is manuallyapplied to the proximal end of rod 134 to push it toward the distal endof the catheter thereby assisting with stretching and refolding orrepleating the balloon into a set of small folds or pleats to create asmaller diameter profile for easier withdrawal of the deflated balloonthrough canula 126. In FIGS. 9A-9C, in addition to using rod 134 tostretch the deflated balloon 116, a rotational force (as indicated byarrows 142) is applied to knob 136 to rotate rod 134 causing balloonelement 116 to be wrapped around rod 134, as best seen in FIG. 9C,thereby further reducing the profile of the deflated balloon.

FIGS. 10-12 illustrate a dilatation balloon tensioning apparatusaccording to a third embodiment of the present invention. The balloondilatation catheter apparatus 210 in FIGS. 10A-10C generally comprises aproximal end catheter sleeve portion 212, a middle sleeve portion 214,and a balloon or inflation element 216 at the distal end of thecatheter. As best seen in FIG. 10B, proximal end catheter sleeve portion212 comprises a tubular shell portion 218 with external threads 225 atits proximal end and a region adjacent to the threaded region forhousing a spring element 222.

Cap element 224 includes a centrally-located axial bore 227 throughwhich fluid 240 can be introduced to or withdrawn from catheter 210, andalso has internal threads sized to mate with the external threads 225 atthe proximal end of the shell portion 218. A gasket, seal, or O-ring229, or a similar fluid-sealing element, having a centrally-locatedaperture, is disposed at the proximal end of the region of shell portion218 which houses spring 222. As seen in FIGS. 10A-10C, cap element 224is loosely threaded onto shell portion 218, and there is no compressionof spring 222, the condition in which catheter 220 would ordinarily beshipped and stored. Balloon element 216 is shown extended, as best seenin FIG. 10C, and is preferably pleated or folded for compactness.

At the distal end of the region for housing spring element 222 (i.e., atthe end opposite from where the cap 224 is threaded onto branch 218), adisc element or circular fitting 230 is sized to slide inside the regionhousing spring element 222 so as to compress the spring element bydisplacement in the proximal direction or to decompress the springelement by displacement in the distal direction. Associated with discelement 230 is axially moveable rod element 234 (which may or may not bephysically connected to disc element 230) which runs axially through theinterior of the catheter from the distal side of disc element 230 to thesealed tip portion 228 of balloon 216. Rod element 234 may or may not bephysically connected to or may or may not engage balloon tip portion228. Rod element 234 operating in conjunction with disc element 230 thuscan act like a piston to alternately compress and allow decompression ofspring element 222.

Also shown in FIGS. 10A-10C, although it is typically not attached tocatheter apparatus 210, is a small diameter canula 226 which provides achannel for the catheter apparatus through a bone portion into the boneinterior. Balloon element 216 must be able to slide through the hollowinterior of canula 226 during insertion of the catheter and, moreimportantly, during removal of the catheter after the balloon hasundergone an inflation/deflation cycle.

In FIGS. 11A-11C, catheter apparatus 210 of FIGS. 10A-10C is shown withcap element 224 screwed down resulting in at least partially compressingspring element 222 in preparation for use. Also in FIGS. 11A-11C,pressurized fluid 240 has been introduced through axial bore 227,through the interior of proximal sleeve portion 212, and through theinterior of middle sleeve portion 214 to fully inflate balloon 216. Asballoon 216 is inflated, it expands in diameter and shortens in lengthcausing rod 234 to move in a proximal direction, thereby displacing discelement 230 in a proximal direction and further compressing springelement 222.

In FIGS. 12A-12C, dilatation pressure is removed and fluid 240 iswithdrawn from balloon 216 and from the interior of catheter 210 throughaxial bore 227. In a preferred embodiment, a vacuum may be applied tothe proximal end of axial bore 227 to assist in withdrawing fluid andfully collapsing balloon 216. As balloon 216 becomes deflated, the forceexerted by the compressed spring element 222 becomes greater than theforce exerted by the collapsing balloon. Eventually this results indisplacing disc element 230 toward the distal end of the catheter, inturn driving rod 234 in the distal direction, and thereby stretching andtensioning balloon 216. This automatic tensioning of the balloon elementupon deflation assists in collapsing, folding and/or pleating theballoon to minimize its lateral profile for easier withdrawal throughthe small diameter interior channel of canula 226.

FIGS. 13-16 illustrate a dilatation balloon tensioning apparatusaccording to a fourth embodiment of the present invention. The balloondilatation catheter apparatus 310 in FIGS. 13A-13C generally comprises aproximal end catheter sleeve portion 312, a middle sleeve portion 314,and a balloon or inflation element 316 at or near the distal end of thecatheter. As best seen in FIG. 13B, proximal end catheter sleeve portion312 comprises a branched or Y-shaped element, of which one arm or branch318 comprises a tubular shell with external threads 325 at its proximalend, and the second arm or branch 320 comprises a fluid inlet/outletconduit for introducing pressurized fluid 340 into catheter 310 forinflating balloon 316 or for withdrawing fluid 340 after a dilatationprocedure.

The tubular shell of branch 318 comprises a region adjacent to thethreaded region for housing a spring element 322. Cap element 324 hasinternal threads and is sized to mate with the external threads 325 atthe proximal end of branch 318. As seen in FIGS. 13A-13C, the capelement 324 is loosely threaded onto branch 318, and there is nocompression of spring element 322, the condition in which catheter 310would ordinarily be shipped and stored. Balloon element 316 is shownextended, and, as seen in FIGS. 13A and 13C, is preferably pleated orfolded for compactness.

At the distal end of the region for housing spring element 322 (i.e., atthe end opposite from where the cap 324 is threaded onto branch 318), adisc element or circular fitting 330 is sized to slide inside the regionhousing spring element 322 so as to compress the spring element bydisplacement in the proximal direction or to decompress the springelement by displacement in the distal direction. Associated with discelement 330 is axially moveable rod element 334 (which may or may not bephysically connected to disc element 330) which runs axially through theinterior of the catheter from the distal side of disc element 330 to thesealed tip portion 328 of balloon 316. Rod element 334 may or may not bephysically connected to or may or may not engage balloon tip portion328. Rod element 334 operating in conjunction with disc element 330 thuscan act like a piston to alternately compress and allow decompression ofspring element 322.

Also shown in FIGS. 13A-13C is a canula element 326. In this embodimentof the invention, however, the canula element 326 does more than justprovide a channel through a bone for inserting or removing the catheterapparatus. In this embodiment, the distal section of catheter sleeveportion 312 includes external threads 336. The proximal end of canula326 is not open, as was the case for the previously described inventionembodiments. Instead, canula 326 is sealed at its proximal end by aplate member 337 having a threaded central bore 338, the threads beingsized to mate with external threads 336. Thus, by turning canula 326around the axis of sleeve portion 312, the position of canula 326 can beadjusted relative to balloon 316 by axial movement along the threadedportion of sleeve 312.

In this embodiment of the present invention, balloon element 316 isdesigned to be longer than the maximum length needed to fill the bonecavity being treated. By adjusting the position of canula 326 along thedistal threaded portion of sleeve 312, a surgeon can expose a length ofballoon element 316 just sufficient to fill a given bone cavity beforeinserting the balloon into the bone cavity and inflating it. In thisway, a standard catheter apparatus with a standardized balloon elementin accordance with the present invention can be easily customized foreach application thereby avoiding the need to prepare and stock amultiplicity of balloon lengths.

In FIGS. 14A-14C, catheter apparatus 310 of FIGS. 13A-13C is shown withcap element 324 screwed down resulting in at least partially compressingspring element 322 in preparation for use. In FIGS. 15A-15C, pressurizedfluid 340 has been introduced through branch 320, through a part of theinterior of proximal sleeve portion 312, and through the interior ofmiddle sleeve portion 314 to fully inflate the exposed portion ofballoon 316. As seen best in FIG. 15B, the proximal end of balloon 316is constrained from expanding beyond the internal diameter of canula 326by the walls of canula 326. As balloon 316 is inflated, at least inpart, it expands in diameter and shortens in length causing rod 334 tomove in a proximal direction, thereby displacing disc element 330 in aproximal direction and further compressing spring element 322.

In FIGS. 16A-16C, dilatation pressure is removed and fluid is withdrawnfrom balloon 316 and from the interior of catheter 310 through fluidinlet/outlet branch 320. In a preferred embodiment, a vacuum may beapplied to the proximal end of branch 320 to assist in withdrawing fluidand fully collapsing balloon 316. As balloon 316 becomes deflated, theforce exerted by the compressed spring element 322 becomes greater thanthe force exerted by the collapsing balloon. Eventually this results indisplacing disc element 330 toward the distal end of the catheter, inturn driving rod 334 in the distal direction, and thereby stretching andtensioning balloon 316. This automatic tensioning of the balloon elementupon deflation assists in collapsing, folding and/or pleating theballoon to minimize its lateral profile for easier withdrawal.

FIGS. 17-21 illustrate a dilatation balloon tensioning apparatusaccording to a fifth embodiment of the present invention. The balloondilatation catheter apparatus 410 in FIGS. 17A-17C generally comprises aproximal end catheter sleeve portion 412, a middle sleeve portion 414,and a balloon or inflation element 416 at or near the distal end of thecatheter. As best seen in FIG. 17B, proximal end catheter sleeve portion412 comprises a branched or Y-shaped element, of which one arm or branch418 comprises a tubular shell with external threads 425 at its proximalend, and the second arm or branch 420 comprises a fluid inlet/outletconduit for introducing pressurized fluid 440 into catheter 410 forinflating balloon 416 or for withdrawing fluid 440 after a dilatationprocedure.

The tubular shell of branch 418 comprises a region adjacent to thethreaded region for housing a spring element 422. Cap element 424 hasinternal threads and is sized to mate with the external threads 425 atthe proximal end of branch 418. As seen in FIGS. 17A-17C, the capelement 424 is loosely threaded onto branch 418, and there is nocompression of spring element 422, the condition in which catheter 410would ordinarily be shipped and stored. Cap element 424 further includesa centrally-located axial bore 427 to accommodate a rod element 434 ashereinafter described. Balloon element 416 is shown extended, and, asseen in FIGS. 17A and 17C, is preferably pleated or folded forcompactness.

Push rod 434, having a knob portion 436 at its proximal end, is slidablypositioned inside the catheter and is sized to extend axially the fulllength of catheter 410. Push rod 434 extends through the central bore427 of cap 424, through a sealing gasket 421, which acts like a bushingfor supporting and centering rod 434, through the center of springelement 422 and the interior of sleeves 412 and 414, and through theinterior of balloon 416 to the sealed tip portion 428. In one variationof this invention embodiment, rod 434 may be connected to or capable ofengaging tip portion 428 to facilitate twisting or wrapping balloonelement 416 about rod 434 following a dilatation and deflation cycle.

At the distal end of the region for housing spring element 422 (i.e., atthe end opposite from where the cap 424 is threaded onto branch 418), adisc element or circular fitting 430 is sized to slide inside the regionhousing spring element 422 so as to compress the spring element bydisplacement in the proximal direction or to decompress the springelement by displacement in the distal direction. Disc element 430 has acentrally-located axial bore to accommodate axially moveable rod element434. Rod element 434 may or may not be physically connected to balloontip portion 428. Rod element 434 operating in conjunction with discelement 430 thus can act like a piston to alternately compress and allowdecompression of spring element 422.

Also shown in FIGS. 17A-17C, although it is typically not attached tocatheter apparatus 410, is a small diameter canula 426 which provides achannel for the catheter apparatus through a bone portion into the boneinterior. Balloon element 416 must be able to slide through the hollowinterior of canula 426 during insertion of the catheter and, moreimportantly, during removal of the catheter after the balloon hasundergone an inflation/deflation cycle.

In FIGS. 18A-18C, catheter apparatus 410 of FIGS. 17A-17C is shown withcap element 424 screwed down resulting in at least partially compressingspring element 422 in preparation for use. In FIGS. 19A-19C, pressurizedfluid 440 has been introduced through branch 420, through a part of theinterior of proximal sleeve portion 412, and through the interior ofmiddle sleeve portion 414 to fully inflate balloon 416. As balloon 416is inflated, it expands in diameter and shortens in length causing rod434 to move in a proximal direction, thereby displacing disc element 430in a proximal direction and further compressing spring element 422.

In FIGS. 20A-20C, dilatation pressure is removed and fluid is withdrawnfrom balloon 416 and from the interior of catheter 410 through fluidinlet/outlet branch 420. In a preferred embodiment, a vacuum may beapplied to the proximal end of branch 420 to assist in withdrawing fluidand fully collapsing balloon 416. As balloon 416 becomes deflated, theforce exerted by the compressed spring element 422 becomes greater thanthe force exerted by the collapsing balloon. Eventually this results indisplacing disc element 430 toward the distal end of the catheter, inturn driving rod 434 in the distal direction, and thereby stretching andtensioning balloon 416. This automatic tensioning of the balloon elementupon deflation assists in collapsing, folding and/or pleating theballoon to minimize its lateral profile for easier withdrawal throughthe small diameter interior channel of canula 426. In FIGS. 21A-21C, inaddition to using rod 434 to stretch the deflated balloon 416, arotational force (as indicated by arrows 442) is applied to knob 436 torotate rod 434 causing balloon element 416 to be wrapped around rod 434,as best seen in FIG. 21C, thereby further reducing the profile of thedeflated balloon.

FIGS. 22-25 illustrate a dilatation balloon tensioning apparatusaccording to a sixth embodiment of the present invention. The balloondilatation catheter apparatus 510 in FIGS. 22A-22D generally comprises aproximal end catheter sleeve portion 512, a middle sleeve portion 514,and a balloon or inflation element 516 at or near the distal end of thecatheter. As best seen in FIG. 22B, proximal end catheter sleeve portion512 comprises a branched or Y-shaped element, of which one arm or branch518 comprises a tubular shell with external threads 525 at its proximalend, and the second arm or branch 520 comprises a fluid inlet/outletconduit for introducing pressurized fluid 540 into catheter 510 forinflating balloon 516 or for withdrawing fluid 540 after a dilatationprocedure.

Cap element 524 has internal threads and is sized to mate with theexternal threads 525 at the proximal end of branch 518. As seen in FIGS.22A-22D, the cap element 524 is loosely threaded onto branch 518, andthere is no compression of a spring element 522, located inside balloon516, the condition in which catheter 510 would ordinarily be shipped andstored. Balloon element 516 is shown extended, and, as seen in FIGS. 22Aand 22C, is preferably pleated or folded for compactness.

An axially moveable rod element 534 having a head portion 530 at itsproximal end runs axially through the interior of the catheter from thedistal side of cap element 524 to the sealed tip portion 528 of balloon516. Rod element 534 may or may not be physically connected to balloontip portion 528. The head portion 530 of rod 534 moves axially within aregion in the interior of branch 518 as rod 534 slides toward or awayfrom tip portion 528.

At the distal end of rod 534 and located inside balloon 516 is a springtensioning system comprising a spiral spring element 522 wrapped aroundat least a portion of rod 534. FIG. 22D is an enlarged view of theballoon end of the catheter which better shows spring element 522spiraling around the distal end of rod 534. As best seen in FIG. 22D,the distal end of rod 534 in one embodiment may comprise two telescopingrod sections consisting of a hollow tubular section 546 and asmaller-diameter section 547 sized to slidably fit inside the hollowinterior of section 546 and terminating in a bulbous rod tip 548. Springelement 522 is a spiral spring having a diameter smaller than the outerdiameter of rod section 546 but larger than the outer diameter of rodsection 547. Spring element 522 is not secured at either end butoccupies a region bounded at the proximal end by the distal end of rodsection 546 and at the distal end by the proximal surface of rod tip548.

In FIGS. 23A-23D, catheter apparatus 510 of FIGS. 22A-22D is shown withcap element 524 screwed down resulting in at least partially compressingspring element 522 by the distal movement of rod section 546 relative torod section 547, in preparation for use. In FIGS. 24A-24D, pressurizedfluid 540 has been introduced through branch 520, through a part of theinterior of proximal sleeve portion 512, and through the interior ofmiddle sleeve portion 514 to fully inflate balloon 516. As balloon 516is inflated, it expands in diameter and shortens in length causingfurther inward telescoping of rod section 547 into rod section 546 (asbest seen in FIG. 24D), thereby further compressing spring element 522.

In FIGS. 25A-25D, dilatation pressure is removed and fluid is withdrawnfrom balloon 516 and from the interior catheter 510 through fluidinlet/outlet branch 520. In a preferred embodiment, a vacuum may beapplied to the proximal end of branch 520 to assist in withdrawing fluidand fully collapsing balloon 516. As balloon 516 becomes deflated, theforce exerted by the compressed spring element 522 becomes greater thanthe force exerted by the collapsing balloon. Eventually this results inan outward telescoping of rod section 547 out of rod section 546 drivenby the decompression of spring element 522, and thereby stretching andtensioning balloon 516. This automatic tensioning of the balloon elementupon deflation assists in collapsing, folding and/or pleating theballoon to minimize its lateral profile for easier withdrawal throughthe small diameter interior channel of canula 526.

Apparatus according to the present invention can be utilized in avariety of ways. As previously discussed, a principal intendedapplication for the apparatus and methods of this invention is intreating vertebral fractures by dilating the interior of a vertebralelement using a balloon catheter. FIGS. 26-33 illustrate variousspecific applications of apparatus and methods according to thisinvention in treating vertebral fractures.

For example, FIGS. 26A-26D schematically illustrate the treatment of apartially collapsed vertebral segment with an apparatus according to oneembodiment of this invention. FIG. 26A schematically illustrates across-section of a vertebral segment 60 comprising an interior region 62filled with cancellous, or spongy, bone, and left and right pedicleportions 64 and 66 respectively. As seen in FIG. 26A, straight-lineaccess holes have been drilled or otherwise created through pedicleportions 64 and 66 and into the adjacent cancellous bone in interiorregion 62 so as to meet and form a V-shaped passageway from the exteriorof vertebral segment 60 through interior region 62.

As shown in FIG. 26B, a catheter guidewire 67 may then be threadedthrough the V-shaped passageway. As shown in FIG. 26C, a catheterapparatus 68 according to the present invention is introduced into theV-shaped passageway along guidewire 67 so as to position all of theuninflated balloon element 69 of the catheter apparatus inside interiorregion 62. As shown in FIG. 26D, once balloon element 69 is properlypositioned in region 62, the balloon element can be inflated, expandingagainst the surrounding cancellous bone and thereby restoring the shapeand size of the vertebral segment close if not identical to itspre-injury configuration. Following this procedure, balloon element 69is deflated and its lateral profile is reduced by stretching,tensioning, folding or pleating the balloon element utilizing theautomatic or manual tensioning and/or twisting techniques previouslydescribed for a catheter apparatus in accordance with this invention.Once the lateral profile of balloon element 69 is sufficiently reduced,catheter apparatus 68, including balloon element 69, can be easilywithdrawn from the vertebral segment.

FIGS. 27A-27D generally correspond respectively to FIGS. 26A-26D, asdescribed above, except that in FIGS. 27A-27D, after the V-shapedpassageway is created through vertebral segment 60, canula elements 70and 71 are inserted respectively into the passages through pedicleportions 64 and 66. As seen in FIG. 27C, the catheter apparatus 78 usedwith this embodiment of the invention includes a balloon element 79which is longer than the length of the V-shaped passageway throughinterior region 62. As a result, a proximal-end portion of balloonelement 79 remains in canula 70 and a distal-end portion of balloonelement 79 is in canula 71. As seen in FIG. 27D, when balloon element 79is inflated, only the middle portion of the balloon which is insideregion 62 can fully inflate. The inflation of the proximal and distalends of balloon element 79 is constrained by the inner wallsrespectively of canula elements 70 and 71. The canula elements 70 and 71prevent the expansion forces exerted by the inflated balloon inside thepassages through pedicle portions 64 and 66 from rupturing theserelatively fragile bones.

FIGS. 28A-28E schematically illustrate a cross-section of a vertebralsegment 80 comprising an interior region 82 filled with cancellous bone,and left and right pedicle portions 84 and 86 respectively. As seen inFIG. 28A, a curved passageway has been created through left pedicleportion 84, through the cancellous bone in region 82, and through theright pedicle portion 86 to form a U-shaped channel from the exterior ofvertebral segment 80 through interior region 82.

As shown in FIG. 28B, canula elements 73 and 74 are positionedrespectively in the passages through left pedicle portion 84 and rightpedicle portion 86. As seen in FIG. 28C, a guidewire 87 may then bepositioned in the passageway through the vertebral segment 80. As seenin FIG. 28D, a catheter 88 in accordance with the present invention,having a balloon element 89, may then be positioned along guidewire 87such that a middle portion of balloon element 89 is in interior region82. Balloon element 89 is shown longer than the entire passagewaythrough vertebral segment 80. As a result, when balloon element 89 is inplace, a proximal-end portion of balloon element 89 extends completelythrough canula element 73 in left pedicle portion 84 and a distal-endportion of balloon element 89 extends completely through canula element74 in right pedicle portion 86. In a variation of this embodiment,balloon element 89 may be fabricated so as to be pre-curved for easierplacement and better fit when inflated inside the U-shaped channel.

As seen in FIG. 28E, upon inflation of balloon element 89, only themiddle portion inside interior region 82 can fully expand. As seen inFIG. 29, while balloon element 89 is in place and inflated, the proximaland distal ends of balloon element 89 are outside vertebral segment 80and therefore accessible to the surgeon's hands 81 or to instruments.

FIG. 30 schematically illustrates a cross section of a vertebral segment160 being treated with a catheter apparatus 162 which utilizes apre-curved internal guidewire 163 but without a spring tensioningelement according to another embodiment of the present invention. Thepre-curved guidewire 163, fabricated for example from nitinol or othermaterial having “memory” properties, assists in properly positioning theballoon element 169 in the preformed channel through the cancellousbone.

In one variation of this invention embodiment, balloon element 169 maybe fabricated as a relatively thinner, more flexible balloon which canbe fully inflated at relatively lower pressures inside vertebral segment160. A more flexible balloon will have more uniform contact with thesurrounding cancellous bone resulting in more surface area for expansionduring inflation and the application of inflation forces at the interiorlocations where such forces are needed for expanding the bone mass.

In another variation of this invention embodiment, following a ballooninflation cycle, balloon element 169 can be deflated and guidewire 163can be utilized similar to the push rods previously described forapplying tension to the deflated balloon element to assist with removalthrough the small-diameter canula 165. If the balloon element 169 is ofa thinner, more flexible construction than those previously described,less tensioning is required for removal. In addition, in the embodimentillustrated in FIG. 30, external tensioning can be applied to the distalend of the catheter, for example by simply pulling on the distal end, toassist in reducing the profile of the deflated balloon element foreasier withdrawal. Alternatively or additionally, tensioning could beapplied to the distal end of the catheter by twisting it.

In still another variation in accordance with this invention, balloonelement 169 could be left in place in the interior of vertebral segment160, and the cavity inside the balloon could be inflated and filled withcement for permanent support of the damaged vertebral element. Duringthis procedure the push rod, if hollow, could be used as a vent tubethat is removed after the balloon is filled with cement. The balloonwalls would contain the liquid cement during the setting period therebypreventing leakage through bone fractures causing medical problems. Evenafter the cement is set, the balloon walls would prevent direct contactbetween the cement and the surrounding bone or tissue. For thisembodiment, the long proximal neck of the balloon would be cut off afterfilling the balloon with cement and after removing the canula.

FIG. 31 schematically illustrates a pre-curved balloon element speciallydesigned for use with a catheter apparatus according to this invention.

FIG. 32 schematically illustrates a cross section of a vertebral segment170 being treated with a catheter apparatus 172 utilizing a pre-curvedguidewire 173 according to another embodiment of the present invention.

FIG. 33 schematically illustrates a cross section of a vertebral segment180 being treated with two catheter apparatuses 182 and 192 according toanother embodiment of the present invention.

In still another embodiment of this invention, the catheter balloonelement for expanding a damaged bone region may be a multi-lumen balloonas described in U.S. Pat. Nos. 5,342,301 and 5,569,195, which patentsare incorporated herein by reference. Use of a multi-lumen balloon canbe of particular value where even using the spring tension or manualwrapping techniques described above will not allow production of adesired size and/or pressure balloon because the balloon profile issimply too large to fit in the canula.

Instead, by using a multi-lumen balloon, one can achieve both largediameters and higher pressures because each individual balloon can holdhigher pressures with thinner walls. Even more important is that thecone or transition regions of the multi-lumen balloons are much thinnerand much more flexible. For example, one could utilize a balloon elementcomprising four balloons/lumens with or without a central lumen for theshaft. Alternatively, with a 5-lumen multi-lumen balloon configuration,the shaft can pass through the central fifth lumen created by the fouroutside lumens or the shaft can pass through one of the four outsidelumens.

As an alternative to a true multi-lumen catheter balloon construction,this embodiment of the invention could be practiced with many of thebenefits of a multi-lumen balloon using several individual balloons in aside-by-side multiple balloon configuration. The individual balloonscould be bonded together or, preferably, one could put an elastomeric ornon-elastomeric sleeve over the group of individual balloons to keepthem aligned during placement at the intended site, inflation andremoval after the inflation cycle.

The multi-lumen and multiple balloon embodiments of this invention asdescribed above may be practiced with straight balloons or withpre-curved balloons configured for easier placement and better fitinside a curved catheter access channel.

FIGS. 34A-34C illustrate yet another embodiment of the presentinvention. FIG. 34A is a schematic elevation view of a balloondilatation apparatus 610 in some respects comparable to the balloondilatation apparatus 210 of FIG. 10A. As best seen in the sectional viewof FIG. 34B, this embodiment of the invention utilizes a stationaryinner shaft or rod element 634 secured at its distal end to the tip 628of inflation or balloon element 616 and a rotatable outer shaft 614. Rodelement 634 runs through a central longitudinal channel in the catheterto the tip 628 of balloon element 616. Outer shaft 614 is connected atits distal end to inflation or balloon element 616 and at its proximalend to a rotatable sleeve element 612, which may advantageously includeoutward projections 615 to assist with manual rotation of the sleeveelement and the connected outer shaft 614.

The proximal end of sleeve element 612 is designed with a lip portion613 to receive and rotatably hold the distal end of a catheter inletconduit 624 through which a fluid 640 can be introduced to inflate theballoon element 616. A gasket, seal, or O-ring 629, or a similarfluid-sealing element, having a centrally-located aperture, is seatedbetween the end of conduit 624 and the lip portion 613 of sleeve element612.

This embodiment of the present invention is especially useful in ductdilatation applications, for example in treating the lacrimal duct. Insuch applications, the inflation or balloon element 616 of apparatus 610is positioned inside a duct that requires dilatation, for example toimprove fluid drainage. Prior to insertion into the duct, the balloonelement 616 can be tightly wrapped around the rod element 634 to reduceits profile and to facilitate insertion with minimal tissue damage ortrauma Once properly positioned, the balloon can be unwrapped byrotating sleeve element 612, for example using projections 615, eitherclockwise or counterclockwise as appropriate.

After it is positioned and unwrapped, balloon element 616 can beinflated with fluid 640 supplied from a pressurized fluid source throughthe hollow central channel running from the proximal end of inletconduit 624 to the interior of the balloon element 616. The balloonelement may be inflated to a desired size and/or a desired inflationpressure, depending on the elastic or inelastic nature of the balloonmaterial, maintained fully inflated for a desired length of time, suchas one to ten minutes, and then deflated by disconnecting the fluidsource and/or withdrawing the fluid, for example by applying a vacuum.This inflation cycle may be repeated two or more times as appropriatefor treating the duct dysfunction.

Following this medical procedure, the balloon or dilatation element isdeflated and sleeve element 612 is again rotated either clockwise orcounterclockwise in order to rewrap the deflated balloon element 616tightly around rod element 634 to reduce its profile for removal fromthe duct. Projections 615 can be especially useful during this step toput additional twisting (rotational) forces on the deflated balloonelement to obtain a tight wrap. Projections 615 can be held manually tomaintain a tight wrap of the deflated balloon element or they can beused to secure this wrapped position such as with an elastic or otherholding element. The rewrapped balloon element can then be relativelyeasily withdrawn from the duct with little or no trauma to surroundingtissue.

It will be apparent to those skilled in the art that other changes andmodifications may be made in the above-described apparatus foradjustable epidermal tissue ingrowth cuffs and methods for using thatapparatus without departing from the scope of the invention herein, andit is intended that all matter contained in the above description shallbe interpreted in an illustrative and not a limiting sense.

1.-34. (canceled)
 35. A method for treating a living being for bone,tissue and/or body duct dilatation comprising the sequential steps of:inserting an inflatable balloon element in an uninflated state into aninterior region, cavity or passage of a damaged, collapsed or deformedbone, tissue or duct through a first of one or more narrow diameteropenings or passageways to position the balloon element at a bodylocation requiring dilatation; inflating the balloon element with aworking fluid to a working pressure and for a time period sufficient tosubstantially completely dilate the interior region, cavity or passageto substantially restore its normal size, shape and/or alignment;deflating the balloon element by withdrawing the working fluid; duringand/or subsequent to said deflating step, stretching and/or folding,pleating or wrapping the balloon element to reduce its profile; and,withdrawing the previously-inflated balloon element through a one ofsaid narrow diameter openings or passageways, which may be the same asor different than said first narrow diameter opening or passageway. 36.A method according to claim 35 wherein said balloon element is inflatedto a working diameter of about 12 mm to about 25 mm during the inflatingstep.
 37. A method according to claim 35 wherein said balloon element isinflated to a working pressure of about 200-400 psi over a relativelyshort balloon working length during the inflating step.
 38. A methodaccording to claim 35 wherein said balloon element is stretched and/orfolded, pleated or wrapped to a diameter of about 4-5 mm or less for thesteps of inserting and/or withdrawing the balloon element.
 39. A methodaccording to claim 35 wherein said balloon element is stretched and/orfolded, pleated or wrapped using at least a balloon tensioning and/orballoon wrapping device selected from the group consisting of active andpassive tensioning and wrapping devices.
 40. A method according to claim35 wherein, following inflation to its working pressure, the balloonelement maintains a high degree of puncture and abrasion resistance. 41.A method according to claim 35 further comprising the step of applying avacuum to the inflated balloon element during the deflating step toassist withdrawal of the working fluid.
 42. A method according to claim35 wherein the balloon element is mounted on the distal end of a hollowtube, and the proximal end of the balloon element is bonded to orintegrally connected with an end of the tube to create a passage throughthe tube to the interior of the balloon element.
 43. A method accordingto claim 42 wherein the distal end of the balloon element is sealed. 44.A method according to claim 43 further wherein a rod element passesthrough the tube and at least a portion of the interior of the balloonelement.
 45. A method according to claim 44 wherein the distal end ofthe balloon element is sealed, said method further comprising the stepof applying axial force manually or automatically to said sealed end ofthe balloon element through said rod element during and/or subsequent tothe deflating step causing tension and axial elongation of the balloonelement.
 46. A method according to claim 45 wherein the rod element isnot attached to the balloon element.
 47. A method according to claim 45wherein the rod element is attached to or otherwise engages the balloonelement.
 48. A method according to claim 47 further comprising the stepof applying rotational force manually or automatically to said rodelement during and/or subsequent to the deflating step causing theballoon element at least in part to wrap around the rod element. 49.(canceled)
 50. (canceled)
 51. A method according to claim 39 wherein theballoon tensioning and/or wrapping device is hydraulically orpneumatically actuated.
 52. A method according to claim 44 furtherwherein said rod element is adjustable in length, said method furthercomprising the step of adjusting the length of said rod element suchthat said rod element applies an axial tensioning to the balloon elementduring the deflating step.
 53. A method according to claim 35 furthercomprising the step of coating the exterior of the balloon element witha coating to improve puncture and abrasion resistance.
 54. A methodaccording to claim 35 further wherein, upon inserting the balloonelement into an interior region, cavity or passage, at least one end ofthe balloon element extends into or completely through a cannula elementpositioned in at least one of the narrow diameter openings orpassageways.
 55. A method according to claim 35 wherein said balloonelement comprises a multi-lumen balloon.
 56. A method according to claim47 wherein said rod element applies axial tensioning to the balloonelement during the deflating step, said method further comprising thestep of applying manual rotational tensioning to the balloon elementduring and/or subsequent to the deflating step.
 57. A method accordingto claim 35 further comprising the steps of positioning a guidewirethrough the interior region, cavity or passage to be dilated, and usingthe guidewire to position the balloon element during the inserting step.58. A method according to claim 57 wherein said guidewire is pre-curved.59. A method according to claim 44 wherein said rod element ispre-curved and fabricated from a material having memory properties. 60.A method according to claim 35 wherein said balloon element ispre-curved.
 61. A method according to claim 35 wherein said balloonelement consists essentially of a non-elastomeric material. 62.-90.(canceled)
 91. A method according to claim 35 wherein the body part tobe treated is a vertebral segment, said method further comprising thestep of forming a passageway including at least one opening from outsidethe vertebral segment into an interior region of the vertebral segment.92. A method according to claim 91 wherein said passageway comprises aV-shaped or U-shaped duct through the interior region of the vertebralsegment.
 93. A method according to claim 92 wherein the balloon elementis positioned in the V-shaped or U-shaped duct.
 94. A method accordingto claim 91 further comprising the steps of positioning a cannulaelement in at least one of the openings into the interior region of thevertebral segment and inserting the balloon element through the cannulaelement such that a portion of the balloon element is inside the cannulaelement during the inflation step.
 95. A method according to claim 91wherein at least two openings are formed into the interior region, saidmethod further comprising the steps of positioning a cannula element ineach opening and inserting the balloon element through the cannulaelements such that a proximal portion of the balloon element is inside afirst of the cannula elements and a distal portion of balloon element isinside a second of the cannula elements during the inflation step.
 96. Amethod according to claim 95 wherein said balloon element is long enoughto extend from outside the first cannula element, through the interiorregion, to outside the second cannula element.
 97. A method according toclaim 96 further comprising the step of simultaneously pulling on eachend of the balloon element after the inflating step to reduce theprofile of the balloon element prior to the withdrawing step.
 98. Amethod according to claim 91 wherein the guidewire is pre-curved andmade of a material having memory properties.
 99. A method according toclaim 91 wherein the balloon element is fabricated to be pre-curved.100. A method according to claim 91 wherein at least two openings areformed into the interior region, said method further comprising thesteps of inserting a balloon element into the interior region througheach opening and inflating both of the balloon elements.